There is disclosed in DE-B-No. 36 31 927, such a light supply device in which light is radiated from a light source to the proximal end of a photo-conductor of an endoscope through a revolving filter plate with the primary colour areas impermeable to light, and permeable to light, for illuminating an object to be examined.
Such a device has the disadvantage that because the transition period between the bright phase and the dark phase is relatively lengthly, the time during which the radiated light is of maximum intensity is restricted to the extent that the resulting light losses cause impairment of the image transmission.